This invention relates to an apparatus for electrophoresis and, more particularly, to an improved gel layer interface adapted to be interposed between the floor of an electrophoresis chamber and an electrophoresis plate.
Electrophoresis is a well-known technique for separation of protein fractions under the influence of an electric field. The material to be electrophoresed is placed on a gel which may be agarose gel cast on a substrate. Typical substrates commonly used are Mylar, a DuPont trademark for a polyester film and Lexan, a General Electric trademark for a polycarbonate film. Among the parameters to be considered during electrophoresis are voltage, amperage, heat and time. As voltage is increased between opposite ends of the electrophoresis gel, the electrophoretic velocity of movement is increased proportionately. However, absent other changes in parameters, the heat increase resulting from a voltage increase becomes a limiting factor. The mobility of the proteins is increased as temperature increases but the proteins are easily denatured and care must be taken generally not to exceed 50.degree. C. Higher temperatures lead to greater evaporation, which increases the ionic strength and, higher temperatures also increase buffer movement thereby tending to deplete a buffer reservoir. Longer running time merely increases the opportunity for problems such as excessive heat and buffer depletion.
When electrophoresis is performed within a chamber such as the REP System marketed by Helena Laboratories Corporation of Beaumont, Tex., the assignee of the present application, the floor or bottom of the electrophoresis chamber is typically made of metal which is both a thermal conductor and an electrical conductor. The electrophoresis plate, e.g., the gel cast on the substrate, is placed on the metal chamber floor, the sample is placed on the gel, and the sample is subjected to the voltage gradient and elevated temperature.